The Culligan D-40A filter is a Carbon Block 10" filter for many Culligan undersink drinking water systems. educes the bad taste and odor of chlorine as well as sediment, lead, mercury, chloramine, atrazine, lindane, dirt, sand, asbestos, silt, rust, scale, cytsts such as cryptosporidium and giardia, turbidity, and Class I particulates.Features: